When the excitation line frequency lies with an electronic absorption band, Raman scattering intensities are enhanced by as much as 10 to the 6th power times. The enhanced bands correspond to parts of the birational fine structure of the electronic absorption. The phenomenon is called the resonance Raman effect. Resonance Raman signals should give detection limits about as low as spectrophotometry, and perhaps lower in favorable cases. More importantly, resonance Raman bands are typically a 5-25 wavenumbers wide (about 0.1 - 0.6 nm at 500 nm). Because of the extremely narrow bandwidth of the signals, the resonance Raman effect offers a selectivity impossible with electronic absorption spectroscopy or molecular fluorescence spectroscopy. It is possible to distinguish closely related molecules and to make quantitative measurements of a constituent in a matrix with a similar absorption spectrum. Applications are proposed to various analytical problems of clinical and pharmaceutical interest.